External additive for toner, toner covered with external additive, development agent, toner container, and image forming apparatus

Abstract

An external additive for toner that contains a resin particle and two or more kinds of particulates having different compositions present on the resin particle.

What is claimed is: 
     
       1. A toner, comprising:
 a mother toner particle comprising a binder resin; and 
 an external additive for toner consisting of a resin particle and a plurality of metal oxide particulates comprising different compositions present on the resin particle, 
 wherein the external additive for toner is present on the mother toner particle, and 
 the plurality of metal oxide particulates uniformly covers a surface of the resin particle with a single layer. 
 
     
     
       2. The toner according to  claim 1 , wherein the binder resin comprises at least one selected from the group consisting of a non-modified polyester consisting of an ester bonding unit, a modified polyester comprising an ester bonding unit and a bonding unit other than the ester bonding unit, and a crystalline polyester. 
     
     
       3. A two component development agent, comprising:
 the toner of  claim 1 ; and 
 a carrier. 
 
     
     
       4. A toner container, comprising:
 a container; and 
 the toner of  claim 1 , 
 wherein the toner container is detachably attachable to an image forming apparatus. 
 
     
     
       5. A toner container, comprising:
 a container; and 
 the two component development agent of  claim 3 , 
 wherein the toner container is detachably attachable to an image forming apparatus. 
 
     
     
       6. An image forming apparatus, comprising:
 an image bearing member; 
 a charging device to charge a surface of the image bearing member to form a latent electrostatic image thereon; 
 a development device to develop the latent electrostatic image with the toner of  claim 1  to form a toner image on the surface of the image bearing member; 
 a transfer device to transfer the toner image to an image support member; and 
 a fixing device to fix the toner image on the image support member to obtain a fixed image. 
 
     
     
       7. The toner of  claim 1 , wherein the metal oxide particulates have a volume average particle diameter Dv of 100 nm or less. 
     
     
       8. The toner of  claim 1 , wherein the metal oxide particulates have a volume average particle diameter Dv of from 6 nm to 80 nm. 
     
     
       9. The toner of  claim 1 , wherein the plurality of metal oxide particulates comprises different kinds of metal compound particles. 
     
     
       10. The toner of  claim 1 , wherein the plurality of metal oxide particulates comprises a silica-containing particle and a non-silica-containing particle. 
     
     
       11. The toner of  claim 1 , wherein at least one of the metal oxide particulates has a hydrophobized surface. 
     
     
       12. The toner of  claim 1 , wherein the resin particle is selected from the group consisting of a non-cross-linked acrylic resin, a cross-linked acrylic resin, a non-cross- linked polyethylene resin, and a cross-linked polystyrene resin. 
     
     
       13. The toner of  claim 1 , wherein the mother toner particle further comprises a coloring agent. 
     
     
       14. The toner of  claim 1 , wherein the mother toner particle further comprises a releasing agent. 
     
     
       15. The toner of  claim 14 , wherein the releasing agent is a wax. 
     
     
       16. The toner of  claim 1 , wherein the mother toner particle further comprises a charge control agent. 
     
     
       17. The toner of  claim 1 , wherein the resin particle has a primary particle diameter of from 25 nm to 200 nm. 
     
     
       18. The toner of  claim 11 , wherein an amount of the metal oxide particulates having the hydrophobized surface is from 30 to 95 mass % of a total amount of the resin particle.